The role of Chironomidae in energy flow of a lotic ecosystem

1992 ◽  
Vol 26 (2-4) ◽  
pp. 471-476 ◽  
Author(s):  
Martin B. Berg ◽  
Ronald A. Hellenthal
Keyword(s):  
Energy Flow ◽  
Lotic Ecosystem

Unified Framework II Ecosystem Processes: A Link Between Species and Landscape Diversity

2005 ◽  
Author(s):  
Robert Waide ◽  
Peter M. Groffman
Keyword(s):  
Landscape Ecology ◽  
Nutrient Cycling ◽  
Community Ecology ◽  
Energy Flow ◽  
Ecosystem Processes ◽  
Landscape Diversity ◽  
Ecosystem Ecology ◽  
Unified Framework ◽  
Ecosystem Diversity

The discipline of ecology can be subdivided into several subdisciplines, including community, ecosystem, and landscape ecology. While all the subdisciplines are important to the study of biodiversity, there is great variation in the extent to which their contributions have been analyzed. For example, the role of community ecology in biodiversity studies is well established. In community ecology, the entities of study are species that differ in their properties and generate a web of interactions that, in turn, organize the species into a community. Similar to community ecology, the contribution of landscape ecology to biodiversity is apparent. The entities of study, definable “patches,” are tangible. They differ in their properties and generate a web of interactions that organize the patches into a landscape mosaic. In contrast to community and landscape ecology, the role of ecosystem ecology in biodiversity is less apparent. In ecosystem ecology, it often is not clear what the entities are, and how they are organized. To the extent that ecosystem ecology focuses on energy flow and nutrient cycling, we can define fundamental entities as compartments and vectors in models that depict the flows of water, energy, and nutrients through communities. If we apply diversity criteria to these entities, we can use the term ecosystem diversity to refer to the number of compartments and vectors, the differences among them in type and size, and their organization in promoting energy flow or nutrient cycling. To our knowledge, ecosystem scientists have not yet developed criteria for ecosystem diversity similar to those used for species and landscape diversity. There has been some use of the term “ecosystem diversity” to refer to a diversity of ecosystems, implying a variety of habitats, landscapes, or biomes. As discussed above, we suggest that to define the role of ecosystem ecology in biodiversity studies, the approach should be to study the relationships among species, landscape, and ecosystem diversities (chapters 1 and 13). However, since the concept of ecosystem diversity awaits further development, we adopt a different approach for understanding the role of ecosystem science in biodiversity studies. In this chapter, we examine relationships among ecosystem processes, species diversity, and landscape diversity.

Seasonal variations in phytoplankton and glycollate concentrations in the Menai Straits, Anglesey

1975 ◽  
Vol 55 (3) ◽  
pp. 557-565 ◽  
Author(s):  
R. H. Hasan-Al ◽  
S. J. Coughlan, Aditipant ◽  
G. E. Fogg
Keyword(s):  
Energy Flow ◽  
Natural Waters ◽  
Sea Water ◽  
External Medium ◽  
Trophic Levels ◽  
Turnover Rates ◽  
Organic Fraction ◽  
Subsequent Elution ◽  
Order Of Magnitude

It is now well established that natural phytoplankton populations may liberate a substantial proportion of the carbon fixed in photosynthesis directly into the external medium in the form of dissolved organic matter. Glycollate may be an important component of this extracellular organic fraction, both in culture (Hellebust, 1965) and in the natural environment (Watt, 1966). Nevertheless, it has been difficult to investigate the role of glycollate in the environment because of the lack of a convenient and reliable method for determining its concentration in natural waters. Shah & Fogg (1973) and Shah & Wright (1974), however, have developed a procedure for glycollate analysis in sea water, based on adsorption on to alumina and subsequent elution for determination by the Calkins colorimetric technique, which is both sensitive and not too laborious for routine analyses. Fogg (1966) suggested that glycollate excreted by phytoplankton acts as an extracellular reserve which may be utilized for survival under conditions unfavourable for photosynthesis. Wright & Hobbie (1965) showed that some fresh water bacteria take up glycollate at rates of the same order of magnitude as for acetate and glucose. Glycollate would therefore appear to be of importance in the energy flow between different trophic levels. In order to evaluate these hypotheses it seems important to determine the concentrations and turnover rates of glycollate occurring in natural waters.

scholarly journals The “Metal-Energy-Construction Mineral” Nexus in the Island Metabolism: The Case of the Extractive Economy of New Caledonia

2020 ◽  
Vol 12 (6) ◽  
pp. 2191 ◽  
Author(s):  
Jean-Baptiste Bahers ◽  
Paula Higuera ◽  
Anne Ventura ◽  
Nicolas Antheaume
Keyword(s):  
Renewable Resources ◽  
Energy Flow ◽  
New Caledonia ◽  
Flow Analysis ◽  
Building Blocks ◽  
Economic Activities ◽  
Resource Base ◽  
Nickel Extraction ◽  
The One

The concept of island metabolism strives to implement the principles of social ecology at the island scale. It is, therefore, a question of analyzing the flows of materials and energy passing through these territories, as well as the resource base needed to sustain their activities. We propose to develop a nexus approach to the New Caledonian island metabolism to understand the interactions between biophysical structures and societal, as well as economic, activities. Metals, construction minerals, and energy are good symbols of economies based on the extraction of non-renewable resources. This is why, in this article, we sought to investigate how the “metal-energy-construction mineral” nexus can affect the resilience and metabolic sustainability of the extractive island of New Caledonia. We carried out the Material and Energy Flow Analysis (MEFA) of each nexus subsystem for 2016 and of the nodes of interdependence. We also interrogated the role of importing countries because the island’s metabolism is dominated by the nickel extraction industry. Indeed, the metabolic profile of this island corresponds to the one of a supply territory for other consumption territories. The latter outsource the impacts of their own consumption to New Caledonia. Finally, based on interviews with economic stakeholders, we studied the potential building blocks for the emergence of an industrial symbiosis in the nexus.

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